The problem with using Satellite is that the majority of providers will only provide a downlink, you will still need some other form of connection to the net in order to request files for download, so if the firm is going to be doing alot of sending/uploading then Satellite is not the best option.

If the client wants to run VPN over this connection, then you can forget it. The lag on satellite makes running a VPN impossible.
Where abouts in the UK is this office? The number of places where you cannot get ADSL is now starting to become smaller and smaller - unless they are on on of those "never upgrade" exchanges....